Method of running a blast furnace



Patented June 13,1939 2 2,162,402

UNITED STATES PATENT OFFIC E MEiTHOD F RUNEZZ Z FURNACE Kurt Hiirnemann, Essen, Germany No Drawing. Application February 19, 1938, Serial No. 191,401. In Germany February 20';

6 Claims. (Cl. 75-131) In blast furnace operation it is customary to use part of the blast furnace, it is possible also to rea charge always as nearly as possible uniform in duce dust losses which, in some instances, are composition, any alloying ingredients being disquite considerable. The novel method proposed tributed over the several charges of the mixture makes it possible, furthermore, to give the pig iron and introduced with the ore into the blast furin the blast furnace certain definite characternace. With this procedure, a considerable part of istics by treating it with slags of diiierent nature. the valuable alloying elements are lost for the It is to'be understood that the measures here reason that they enter the slag and are carried off suggested may also be taken in combination in withthe same. Furthermore, a change of the such a way, for instance, that periodically several 9 nature of the slag introduced by the ore to inmediums of reaction and alloying ingredients are 10 fiuence the iron is possible only if large quantities administered by the throat or by blowing-in of reacting substances are added. either simultaneously or successively. Besides, The present invention relates to a method of the discharge of the slag and the forming of a introducing alloying ingredients and reacting new slag with identical or different additions may media such as manganese, chromium, molybbe undertaken several times during one and the 15 denum, titanium, vanadium, lime, soda, etc., into same tapping of the pig. the pig iron bath and involves the withdrawal of Two procedures by which the new method may the Slag from the blast, furnace wh c is be g be put into practice are given hereafter by way operated in the usual manner, whereupon the alof example. loying elements are introduced in the lower part 1. After the introduction of 10 loads of coke of the blast furnace either by the throat or by and ore, loads of coke, ore. and manganese ore blowing in, or both ways. This means that the are brought into the blast furnace, it being under-. mediums to produce reaction and the alloying stood that, where needed, a suitable quantity'of elements are to be introduced to the blast furnace flux such as limestone may be included in the i only after the slag has been drawn oil. The subcharge. After the melting down of the loads stances in question may be introduced in any first introduced, the slag formed is drawn off so suitable chemical or phyiscal condition either by that now the molten pig iron may get into recarrying them in the well known manner with acting relation with the remaining 5 loads. With a cold or hot air blast or gas into the lower part this procedure, only a small percentage of manof the blast furnace, by preference below the ganese is absorbed by the slag, the incurred loss of so belly, or by periodical top charges, 1. e., by changthis valuable ingredient thus being moderate. ing the mixture introduced as regards its weight After the total of the loads introduced have and composition. The advantages of this method been melted down, the second formation of slags are that the slags no longer will absorb important and the iron are tappedin the usual manner quantities of valuablesubstances, making diflicult whereupon the same procedure is repeated as deor preventing their being imparted to the pig iron scribed.

and, furthermore, in that the quantity of slag 2. A large part of the'slag formed is tapped oil produced diminishes and that the slag may be which, owing to its composition, is suited to be prepared or treated in any manner preferred and used for road ballasting. Then, cold or hot lime 0 may be used after its discharge from the furnace in the burnt or unburnt state is blown into the 40 to improve the quality of the pig iron. A' further lower part of the blast furnace by means of cold important advantage is that by theblowing in and/or hot air and/or gases. The slag, thereby method itself an accurately alloyed iron may be enriched with lime, is brought into reacting relamelted such as a charge, for instance, of 100 tons tion with the pig iron desulphurizing it to the of ironwith 1% nickel, no losses of iron being degree required. The second slag and the pig 5 incurred, with the result that it is new technicalare tapped oil then and the same procedure is rely and economically possible to prepare smaller peated. the second slag being suitable fonother quantities of iron of a definite composition in purposes such as the productidn of cement. large blast furnace plants. 1 I claim:

To provide for the time needed by the process 1. Method for the production in blast furnaces of reaction, it may be advisable to run' the blast of ironwhich contains an alloying ingredient such furnace intermittently, meaning that the speed asmansanes h m u .m y u .t1tamum, of the process may have to be varied even to the vanadium, or the like, which consists in the steps Phint of c p pp e of the blast. By the of (1) introducing into the blast furnace a charge blowing-in of valuable substances into the lower of iron ore and fuel, (2)0perating the blast furnace to reduce the iron ore, forming molten iron and slag, (3) drawing of! the slag while retaining the molten iron in the blast furnace, (4) introducing into the blast furnace a secondary charge containing an ore of the alloying metal and fuel, (5) operating the blast furnace to reduce said second charge to metal and slag, and (6) drawing of! the resulting metal comprising iron and said alloying metal.

2. The method according to claim 1 wherein the blast furnace while acting upon the secondary charge is operated at a. reduced rate.

3. Method for the production in blast furnaces of iron which contains an alloying ingredient such as manganese, chromium, molybdenum, titanium, vanadium, or the like, which consists in the steps of (1) introducing into the blast furnace a charge of iron ore and fuel, (2) operating the blast furnace to reduce the iron ore, forming molten iron and slag, (3) drawing of! the slag while retaining the molten iron in the blast furnace, (4) introducing into the blast furnace a secondary charge containing the alloying material (5) operating the blast furnace to assimilate said second charge and (6) drawing oil. the resulting metal comprising iron and said alloying metal.

4. The method acording to claim 3 wherein the blast furnace while acting upon the secondary charge is operated at a reduced rate.

5. Method according to claim 3 wherein the secondary charge is blown into the blast furnace.

6. Method for the production in blast furnaces of iron which contains an alloying ingredient such as manganese, chromium, molybdenum, titanium, vanadium, or the like, which consists in the steps of 1) introducing into the blast furnace a charge of iron ore and fuel, (2) operating the blast furnace to reduce the iron ore, forming molten iron and slag, (3) drawing oil the slag while retaining the molten iron in the blast furnace, (4) introduclng into the blast furnace a secondary charge containing the alloying material, (5) assimilating said second charge, and (6) drawing off the resulting metal consisting of iron and said alloying met KURT HGRNEMANN. 

